Energy supply device of a melting tank

ABSTRACT

The invention relates to an energy supply device of a melting tank. According to the invention, between an electrode plane of the melting tank and a converter for the current supply of the electrode plane, a separatable plug connection is provided in the supply line, between the electrode plane and the converter. Thereby in case of a defect of the converter, the supply line can be cut off simply and rapidly, and the converter either tended to or replaced. In an especially advantageous form of execution the energy supply device has a reserve converter so that, on failing of the converter, by unplugging the plug connection and replugging it so as to set up a plug connection to the reserve converter, the energy feed to the electrode plane can be restored within the shortest possible time.

[0001] The invention relates to an energy supply device of a meltingtank with an electrode plane in the melting tank and a converter forvoltage supply of the electrode plane.

[0002] In a conventional energy supply device of an optical melting tankthe energy feed to the melting tank tales place over the crown (Gowölbe)of the melting tank by combustion of a fossil energy carrier andfurthermore, in the bottom zone of the melting tank by electrodes. Theelectrodes are arranged in several electrode planes and are suppliedwith alternating current at a medium frequency of 10 kHz from severalconverters, in which arrangement to each electrode plane there isassociated in each case a converter.

[0003] The electrode planes are connected to the converters over energysupply lines and control lines, which are permanently wired. If aconverter, there, fails by reason of a technical defect, then thecorresponding electrode plane can no longer be operated. Through theabsent energy feed of the corresponding electrode plane there occurtemperature unbalances in the optical melting tank, so that the latter(tank) altogether can no longer be operated. The operation of the entireoptical melting tank must consequently be interrupted in order to changeor replace the defective converter. Since this latter is firmly wiredwith the electrode plane, it is necessary for a coworker with trainingin electricity to disconnect the defective converter and either torepair it or to replace it. This complicated repair leads to down timeslasting from a few hours to several days.

[0004] The problem of the invention is to further develop an energysupply device of a melting tank in such manner that on failure of anindividual converter the down time of the entire melting tank isminimized, and maintenance operations are simplified.

[0005] This problem is solved with the feature of claim 1.

[0006] According to claim 1, a separatable plug connection is providedbetween an electrode plane and a converter.

[0007] If, in this energy supply device, a converter fails, then samecan be electrically separated from the electrode place by simplypulling-off the plug connection. The severing of the connection can beperformed by semi-skilled personnel, without an especially trainedelectrician being required for the purpose. The separation occurs therewithin an extremely short time and the defective converter can be eitherrepaired, or exchanged for a new converter.

[0008] By the separation of the current supply line between theconverter and in a maintenance operation or a repair, the electrodeplane safety is enhanced, since the converter is electrically completelyseparate from the electrode plane.

[0009] In an especially advantageous mode of execution of the energysupply device, the latter comprises a spare converter which likewise canbe replaced. If a failure of a converter occurs here, then the supplyline between the defective converter and the electrode plane can berapidly cut off, and the supply line of the electrode plane can simplybe changed over to a connection to the reserve converted. It is notnecessary, therefore, immediately to repair or replace the defectiveconverter. The down time of the melting tank is now only the timerequired for the changeover from the defective converter to the spareconverter. There is thus ensured, there, a virtually trouble-freeoperation of the melting tank.

[0010] For the further enhancement of the operating security, in afurther form of execution the plug connection is equipped with an endcontact. The end contact is actuated when the plug connection betweenthe converter and the electrode plane is completely established. Theoperation of the converter is switched over the end contact, in whichprocess the converter is switched free of voltage and current as soon asthe plug connection is cut of f. Therewith the corresponding plugconnection becomes free of voltage and current, even before the plugconnection is completely separated, so that in the event of aninadvertent separation of the plug connection the operating safety ofthe working personnel is guaranteed.

[0011] The end contact can be a mechanical switch or a magnetic switch,such as a reed relay. The end contact can be arranged directly withinthe plug connection or bordering on this.

[0012] If the plug connection is executed as a coaxial plug connection,then the internal conductor is shielded by the outer conductor.

[0013] For the further improvement of the safety of operation, the partof the plug connection that leads to the energy-feeding converter isexecuted as a plug socket. Thereby an inadvertent contacting ofcurrent-conducting lines is precluded.

[0014] In an especially advantageous form of execution each supply linebetween a plurality of electrode planes and a corresponding number ofconverters is connected by a separatable plug connection. Thereby themelting tank can be completely uncoupled from the energy feed of theconverters. By the complete separating of the melting tank from theenergy feed, the operating safety in the maintenance of the melting tankcan be enhanced. There is also possible, there, a complete exchanging ofthe melting tank or of the converters without any major electricalinstallation operations.

[0015] By the providing of a single spare converter, it is possible toreplace the failing converter (only), among the plurality of converters,with the reserve converter, in which operation the down time of themelting tank is further substantially reduced. Since with a plurality ofconverters only a single spare converter is provided as a reserve, theinvestment costs and maintenance costs are reduced.

[0016] If the plug sockets that are connected with the converters arearranged adjacently to one another, the perspicuity over the plugconnection between the converters and the electrode planes is improved.Therewith there is likewise improved the operating safety anddependability of the energy supply device. Through the centralarrangement of the plug connection even semi-skilled personnel canestablish or release the plug connection.

[0017] For the further improvement of perpsicuity, the plug sockets aregrouped in each case adjacently to one another, for example according tofunctional units of the electrode planes. These functional units ofelectrode planes are, for example, the use unit “tank”, the use unit“crucible” and the use unit “lynching” (Lynchen).

[0018] In an especially advantageous mode of execution of the energysupply device, the control lines between each electrode plane and itsallocated converter likewise are connected over separatable plugconnections. Thereby the separating of the converter from the electrodeplane is further facilitated.

[0019] For the further improvement of perspicuity, in each case beside aplug socket for the energy supply to the electrode planes there arearranged one or several control plug connections. There, one side of acontrol plug connection is connected to a control line which is broughttogether with a plug control line of the electrode plane. Thereby theenergy supply line connections and control connections for the converterlie immediately next to one another, and likewise do the supply line andthe control lines for the electrode plane, this facilitating theallocation of the connecting element, whereby the operating safety isenhanced.

[0020] With the aid of a drawing, an example of execution of theinvention is explained in detail.

[0021]FIG. 1 shows a table unit with plug connections.

[0022] In FIG. 1 there is represented a table unit 1 with plugconnections. By the table unit 1 there is established the electricalconnection between an optical melting tank and converters of the opticalmelting tank. In the optical melting tank, in this example of execution,eleven electrode planes are arranged, each electrode plane beingsupplied with energy in each case by one converter.

[0023] On the table-plate of the table unit 1 there are arranged twelvecoaxial plug nozzles 2, which are connected in each case with aconverter over feed lines. Into the coaxial plug sockets 2, coaxialplugs 3 are pluggable which, over flexible feed lines 4, are connectedwith, in each case, one of the electrode planes of the optical meltingtank.

[0024] For the supplying of all eleven electrode planes of the meltingtank, there run eleven flexible supply lines 4, with in each case onecoaxial plug 3, from the melting tank to the table unit 1 and areinserted there into the corresponding coaxial plug sockets 2, wherebythe coaxial plug connections 2, 3 are established. In the interest ofperspicuity in FIG. 1 only one plug connection 2, 3 with feed line isshown. Accordingly in normal operation of the melting tank eleven of thetwelve coaxial plug sockets 2 are occupied, so that in the table unit 1shown in FIG. 1 the coaxial plug socket 2 to the right in front is notoccupied.

[0025] Over the coaxial plug connections 2, 3 and the flexible lines 4the electrode planes are supplied with alternating current at a mediumfrequency of 10 kHz. By reason of the high power requirement the coaxialplug socket 2 and the coaxial plug, as well as the flexible line 4, areconstructed correspondingly thick.

[0026] On the front side surface of the table unit 1 shown in FIG. 1,there are represented twelve control plug sockets 5, 6 in each case twoof the control plug socket 5, 6 are assigned to the coaxial plugconnection 2, 3 and lie adjacent on the front side of the table plate.On the rear side surface of the table unit 1 there are likewise arrangedtwelve control plug sockets 5, 6 which are correspondingly allocated tothe rearward-located coaxial plug connections 2, 3 (not shown).

[0027] Into the first control plug socket 5 there is insertable a firstcontrol plug 7. From each of the first control plugs 7 there runs afirst control line to the respective electrode plane, in which systemthe control line is brought together with the corresponding flexiblesupply line 4 for the current supply.

[0028] Into the second control plug socket 6 there is insertable asecond control plug 8. From each of the second control plugs 8 therelikewise runs a second control line to the respective electrode plane,the second control line being combined with the first control line andthe flexible line 4. By the combining of the flexible line 4 with thefirst and second control lines there occurs a simple allocation amongthe lines to the respective electrode plane.

[0029] Over the first control plug connections 5, 7, the timing signalsare transmitted for the clock control (Taktsteuerung) of the respectiveconverter. Over the second control plug connections 6, 8, furthercontrol signals are transmitted to the converter. To these there belongand on/off signal, a readiness-indicating signal, and a control currentof 0 to 20 mA.

[0030] Into the coaxial plug sockets 2 there are integrated end-contactswitches which are switched only on complete plugging of the coaxialplug 3 into the coaxial socket 2. The converters can be operated onlywhen the end-contact switches are switched. On inadvertent releasing ofthe coaxial plug connection 2, 3, the end-contact switch triggers anemergency shutdown relay with turns off the main switch of therespective converter and therewith the converter itself.

[0031] Beside the coaxial plug socket 2 as well as beside the first andsecond control plug sockets 5, 6 there are arranged identifiers (A1 toA5 and R1 in FIG. 1), which are also correspondingly provided on thecoaxial plug 3 as well as on the first and second control plugs 7, 8, sothat in the plugging together of the plugging connections a correctallocation occurs.

[0032] The table unit 1 is designed in such manner that with connectionof all the consumers (electrode planes) on the table unit 1 the coaxialplug socket 9, the first control plug socket 10 and the second controlplug socket 11 remain free. The unoccupied coaxial plug socket 9 and thefirst and second control plug sockets 10, 11 are connected with a spareconverter (back-up converter). If one of the converters that supply theconnected consumers with energy should fail, then the correspondingcoaxial plug 3 and the first and second control plugs 7, 8 can beuncoupled from the corresponding connections of the defective converterand be inserted into the free coaxial plug socket 9 as well as into thefirst and second control plug sockets 10, 11 of the spare converter.

[0033] Thereby the table unit 1 forms a shunting distributor on which ifnecessary, i.e. on failure of a converter, the plug connections 2, 3, 5,7, 6, 8 are cut off and the flexible supply and control lines 4 are laidto the free coaxial plug socket 9, where the plug connections 9,3; 10,7; 11, 8 to the reserve converter are established.

[0034] In the example of execution shown all of the end-consumers areconnected to one table-unit. In a second form of execution the coaxialplug connections 2, 3 are distributed onto several table units, where ineach table unit the consumers are sorted out according to groups. Forexample, in a first table unit there are arranged eleven coaxial plugsockets for the converters of the eleven consumers (“tanks” (“Wannen”)and beside these eleven coaxial plug sockets there are, in each case,corresponding first and second control plug sockets. On a second tableunit there are arranged nine coaxial plug sockets with in each case afirst and a second control plug socket in order to supply the consumers“Crucibles” (Tiegel) and “Lynches” (Lynchen). The supply lines to theconsumers “Tank” are moved (verlegt) up to the first table unit, wherethey can be flexibly reconnected between (among?) the plug sockets andthe reserve plug socket, and the supply line of the consumers“Crucibles” and “Lynches” are displaced running to the second tableunit, where they likewise can be replugged flexibly between (among ?)the plug sockets and the reserve plug socket. List of reference numbers1: Table unit 2: Coaxial plug socket 3: Coaxial plug 4: Flexible supplyline 5: First control plug socket 6: Second control plug socket 7: Firstcontrol plug 8: Second control plug 9: Coaxial plug socket 10: Firstcontrol plug socket 11: Second control plug socket

1. Energy supply device of a melting tank with an electrode plane in themelting tank, a converter for the voltage supply of the electrode plane,and a separatable plug connection (2, 3) of the supply line (4) betweenthe electrode plane and the converter.
 2. Energy supply device of amelting tank according to claim 1 , characterized by a reserve or spareconverter, in which the supply line (4) of the electrode plane can bechanged from the converter to the spare converter.
 3. Energy supplydevice of a melting tank according to claim 1 or 2 , characterized inthat the plug connection (2, 3) has an end contact, in which the endcontact is switched on by the coupling of the plug connection (2, 3). 4.Energy supply device of a melting tank according to claim 1 , 2 or 3,characterized in that the separatable plug connection (2, 3) is acoaxial plug connection.
 5. Energy supply device of a melting tankaccording to one of the preceding claims, characterized in that theseparatable plug connection comprises a plug (3) and a plug socket (2).6. Energy supply device of a melting tank according to claim 5 ,characterized in that the plug socket (2) is arranged on the connectingline to the converter and the plug (3) is arranged on the connectingline (4) to the electrode plate.
 7. Energy supply device of a meltingtank according to claim 6 , characterized in that the end contact isarranged in the plug socket (2).
 8. Energy supply device of a meltingtank according to one of the preceding claims, characterized by aplurality of electrode planes and a corresponding number of converters.9. Energy supply device of a melting tank according to claim 8 ,characterized in that the plug sockets (2) are arranged adjacently toone another.
 10. Energy supply device of a melting tank according toclaim 8 , characterized in that the plug sockets (2) are arranged ingroups lying adjacent to one another.
 11. Energy supply device of amelting tank according to one of claims 5 to 10 , characterized in thatbeside each plug socket (2) there is arranged at least one control plugconnection.